The present invention relates to a substrate body transfer apparatus. In greater detail, the present invention relates to a substrate body transfer apparatus which has the ability to move a substrate body employed in the semiconductor industry or liquid crystal industry between the inner space of an air conveyance apparatus and the inner space of an external processing apparatuses, without exposing the substrate body to the external atmosphere; this substrate body transfer apparatus is a so-called load-lock chamber or transfer chamber which is capable of isolating or replacing the atmosphere surrounding the substrate body.
Conventionally, in manufacturing processes of semiconductors and the like, a substrate body conveyance apparatus is employed to move the substrate body (for example, a semiconductor wafer) between manufacturing apparatuses used in each process. Examples of this type of conveyance apparatus are, for example, conveyance apparatuses which convey a cassette jig, into which the substrate body is inserted, on a conveyance vehicle, and conveyance apparatuses which convey the substrate bodies one at a time using a robot arm. However, in these conveyance apparatuses, the atmosphere in the space in which the substrate body is processed is the atmospheric air, and it is currently the case that such spaces do not have an atmosphere of sufficiently high cleanliness. Recently, methods have also been employed in which a cassette jig with a substrate body inserted thereinto is conveyed in a sealed container; however, the problems of contamination from the materials of the container and the gasket used to maintain air tightness with respect to the substrate body have not been solved.
An air conveyance apparatus which conveys the substrate body using air (an air bearing) within the conveyance path has been proposed as a method for solving these problems. In these air conveyance apparatuses, the conveyance path can be made a closed type (closed system), so that it is possible to make the surroundings of the substrate body a space having a sufficiently high degree of atmospheric cleanliness. An example of the composition and function of an air conveyance apparatus is shown hereinbelow.
(1) The air conveyance apparatus is provided with a clean space tunnel therewithin, an opening part which forms the entrance and exit of the tunnel, and with an air conveyance surface.
(2) Lift pins which support the periphery of the substrate body and raises and lower it are provided at the air conveyance surface, and the substrate bodies are placed on the lift pins by a transfer hand (for example, the fingers of a robot or the like) of an external processing apparatus at the entrance of the tunnel.
(3) The lift pins are lowered, the substrate body is placed in an airstream comprising highly pure air, and is caused to float, and thereby, the substrate body is conveyed in the direction of the exit of the tunnel.
(4) At the exit of the tunnel, the substrate body, which has been conveyed in the air stream and is hovering at a position at which it is stopped, is lifted and supported by lift pins, and the substrate body is grasped and removed by a transfer hand of an external processing apparatus.
The air conveyance apparatus described above has the advantage that it is possible to convey the substrate body within the clean space tunnel and there are no parts which give rise to particulate matter within the apparatus; however, the following problems occur during transfer to or from other substrate body processing apparatuses at the entrance and the exit of the tunnel.
(1) The atmosphere of the external processing apparatus enters the air conveyance tunnel from the entrance and exit of the air conveyance apparatus, and the highly pure gas within the tunnel becomes contaminated.
(2) When the external processing apparatus is a vacuum apparatus or a reduced pressure apparatus, the highly pure gas within the air conveyance tunnel flows out, and enters into the external processing apparatuses, so that disruptions are caused to the air conveyance function and to the vacuum or reduced pressure functions.
In order to solve these problems, conventionally a so-called load-lock chamber is provided at the transfer part between apparatuses; in this chamber, a transfer hand (vacuum robot or the like) is installed within the chamber, which is placed between two isolating valves (gate valves or the like) which serve to separate the inner and outer atmospheres. However, such currently available products are incapable of sufficiently maintaining an ultra-clean level (a level in which the concentration of impurities is on the order of ppt), which allow almost no particulate matter or contamination, and furthermore, a load-lock chamber having the structure described above can not always be said to be the optimal structure for an air conveyance apparatus.
The present invention has as an object thereof to provide a substrate body transfer apparatus which isolates the atmospheres of external processing apparatuses and an air conveyance apparatus from one another and prevents mutual contamination, makes possible the transfer of substrate bodies at low levels of particulate matter and contamination which satisfy the ultra-clean level, and is optimal for use as a single wafer processing air conveyance apparatus.
The first substrate body transfer apparatus in accordance with the present invention is a substrate body transfer apparatus which has the ability to transfer substrate bodies between the interior space of an air conveyance apparatus and the interior space of external processing apparatuses without exposing the substrate bodies to the external atmosphere, wherein the transfer apparatus is provided with: a vacuum container, the internal pressure of which can be reduced; a partition which horizontally divides the interior of the vacuum container into two chambers, an upper space and a lower space; an opening which is provided in the upper space and which communicates with the interior space of an external processing apparatus; an opening which is provided in the lower space and which communicates with the interior space of the air conveyance apparatus; a circular opening which is provided in the center of the partition; valve seats which are provided in both the upper and lower surfaces along the periphery of this opening; a horizontal disc-shaped upper part valve, which is positioned within the upper space, and may be raised and lowered; a horizontal disc-shaped lower part valve, which is positioned within the lower space, on which the substrate body is positioned, and which may be raised and lowered; a means for raising and lowering the entirety of the upper part valve; and a means for raising and lowering the entirety of the lower part valve.
The second substrate body transfer apparatus in accordance with the present invention is a substrate body transfer apparatus which has the ability to transfer substrate bodies between the interior space of an air conveyance apparatus and the interior space of external processing apparatuses without exposing the substrate bodies to the external atmosphere, wherein the transfer apparatus is provided with: a vacuum container, the internal pressure of which can be reduced; a partition which horizontally divides the interior of the vacuum container into two chambers, an upper space and a lower space; an opening which is provided in the upper space and which communicates with the interior space of the air conveyance apparatus; an opening which is provided in the lower space and which communicates with the interior space of an external processing apparatus; a circular opening which is provided in the center of the partition; valve seats which are provided in both the upper and lower surfaces along the periphery of this opening; a horizontal disc-shaped upper part valve, which is positioned within the upper space, and may be raised and lowered; a horizontal disc-shaped lower part valve, which is positioned within the lower space, on which the substrate body is positioned, and which may be raised and lowered; a means for raising and lowering the entirety of the upper part valve; and a means for raising and lowering the entirety of the lower part valve.
Both the substrate body transfer apparatuses having the composition described above have a vacuum container provided with an entrance and an exit which communicate with the interior space of the air conveyance apparatus and the interior space of an external processing apparatus, and a horizontal disc-shaped upper part valve and lower part valve are housed within the vacuum container, so that after the substrate body has been positioned within a space surrounded by the upper and lower valves and this space has been sealed, it is possible to render this space a vacuum or to replace the air within. Accordingly, a substrate body transfer apparatus is obtained which is capable of isolating the atmospheres of the external processing apparatus and the air conveyance apparatus from one another and preventing mutual contamination, and which is capable of conducting transfer of the substrate body with a low level of particulate matter or contaminants.